Method for re-using expanded styrene

ABSTRACT

A method for re-using unneeded expanded styrene and an apparatus for preparing comminuted expanded styrene that can be used as a starting material for injection molding. The expanded styrene is rendered re-usable through a first step of comminuting expanded styrene, a second step of illuminating far-infra-red light to the expanded styrene comminuted by the first step to reduce its volume, a third step of further comminuting expanded styrene, reduced in volume by the second step, to prepare a granulated material, and a fourth step of injection-molding the granulated material from the third step to prepare a regenerated article.

RELATED APPLICATION DATA

The present application claims priority to Japanese Application No.P10-105028 filed Apr. 15, 1998 which application is incorporated hereinby reference to the extent permitted by law.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to a method for re-using expanded styrene byprocessing used expanded styrene to fabricate regenerated products, andan apparatus used in this method for processing expanded styrene.

2. Description of the Related Art

Expanded styrene is superior in shock-absorption, heat-insulating andheat retaining properties, and hence is used extensively for packaging awide variety of products from electric appliances to food and beverages.

However, this expanded styrene has a drawback that it presents disposaldifficulties when the articles are unpacked and the packaging materialis to be discarded. That is, expanded styrene, which has becomeunnecessary, was simply destroyed or incinerated. However, this disposalsystem is now to be re-considered because ofthe problems of procurementof land-filling sites and public hazards caused by bad smell or smokegenerated on incineration.

In order to meet this request, there has been proposed a processingapparatus for expanded styrene such as is disclosed in JapaneseLaying-Open Patent H-1-89110 or in Japanese Laying-Open PatentH-6-166034. The processing apparatus pulverizes the unneeded expandedstyrene, transports the pulverized product on a belt conveyor andilluminates far-ultra-red light from a far-ultra-red heater providedpartway on the transport path to reduce its volume. If the far-ultra-redlight is illuminated to heat the pulverized product of the expandedstyrene, as in this processing apparatus for the expanded styrene, theused styrene can be reduced in its volume without causing fusiondecomposition or bad smell or elevating the furnace temperature. Thus,the processing apparatus for expanded styrene is meritorious in handlingthe unneeded expanded styrene as a waste material.

However, if the expanded styrene is processed using the above-describedprocessing apparatus, the aforementioned problem cannot be solvedcompletely because the expanded styrene, reduced in its volume onpulverization, is handled as a waste material.

It is therefore desired to re-use the pulverized expanded styrene, thusreduced in its volume, as a starting material for producing aregenerated product. However, the pulverized expanded styrene, thusreduced in its volume, is not uniform in size and shape, such that itcannot be used as a starting material for injection molding.

SUMMARY OF THE INVENTION

It is therefore an object of the present invention to provide a methodfor reusing unneeded used expanded styrene and a processing apparatusfor expanded styrene for producing pulverized expanded styrene.

In one aspect, the present invention provides a method for re-usingexpanded styrene including a first step of comminuting expanded styrene,a second step of illuminating far-infra-red light to the expandedstyrene comminuted by the first step to reduce the volume thereof, athird step of further comminuting expanded styrene, reduced in volume bythe second step, to prepare a granulated material and a fourth step ofinjection-molding the granulated material from the third step to preparea regenerated article.

In this re-using method for expanded styrene, unneeded expanded styreneis first-order comminuted in the first step to a pre-set size. Theexpanded styrene, first-order comminuted in the first step, isilluminated by far-infra-red light in the second step and therebyreduced in volume.

The expanded styrene, reduced in volume by the second step, issecond-order comminuted in the third step to a granulated materialhaving uniform size and shape. The granulated material from the thirdstep is injection-molded in the fourth step to produce a regeneratedarticle. This enables the unneeded expanded styrene to be re-used as astarting material for a regenerated article.

In another aspect, the present invention provides an apparatus forprocessing expanded styrene including first comminuting means forfirst-order comminuting charged expanded styrene, heating means forheating and reducing the volume of the expanded styrene first-ordercomminuted by the first comminuting means by illuminating thefar-infra-red light thereon and second comminuting means for first-ordercomminuting the expanded styrene reduced in volume by the heating meansto prepare a granulated material.

The first comminuting means first-order comminutes the unneeded expandedstyrene to a pre-set size. The expanded styrene, first-order comminutedby the first comminuting means, is routed to the heating means.

The heating means illuminates the far-infra-red light on the expandedstyrene, first-order comminuted by the first comminuting means, to heatthe expanded styrene to reduce its volume. The expanded styrene, reducedin volume by this heating means, is sent to the second comminutingmeans.

The second comminuting means second-order comminutes the expandedstyrene, first-order comminuted by the heating means, to render theexpanded styrene uniform in size and shape to prepare a granulatedstarting material.

The granulated starting material, prepared by this processing apparatusfor expanded styrene, is charged into, for example, an injection moldingmachine so as to be used as a starting material for a regeneratedarticle as the product of the injection molding machine.

In the re-using method for the expanded styrene according to the presentinvention, unneeded expanded styrene is comminuted in the first step tothe comminuted expanded styrene which is illuminated in the second stepby the far-infra-red light and thereby reduced in volume. The expandedstyrene, thus reduced in volume, is further comminuted in the third stepto give a granulated starting material which is injection-molded in thefourth step to produce a regenerated article. Thus, the unneededexpanded styrene can be re-used without producing pollution problemsattributable to increased volume of industrial wastes and disposalthereof on incineration.

Moreover, the processing apparatus for expanded styrene according to thepresent invention is configured for first-order comminuting unneededexpanded styrene by the first comminution means, illuminating thefar-infra-red light by heating means to reduce its volume andsecond-order comminuting the material reduced in volume by second-ordercomminuting means to prepare the granulated starting material. Thisgives a re-usable starting material uniform in size and shape.

Therefore, if the unneeded expanded styrene is processed using theprocessing apparatus for expanded styrene according to the presentinvention, the expanded styrene, which is not needed, can be used as astarting material for a regenerated article, without handling theunneeded expanded styrene as a waste material, thus completelyeliminating the pollution of other problems attributable to increasedvolume of the industrial wastes or disposal thereof on incineration.

Moreover, since the present processing apparatus for expanded styreneilluminates the far-infra-red light on the unneeded expanded styrene forreducing its volume without causing decomposition on fusion, it ispossible to prevent bad smell or smoke of combustion attributable todecomposition on fusion of the expanded styrene.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic view showing a unitary type processing apparatusfor expanded styrene according to the present invention.

FIG. 2 is a side view of a pulverizing roll.

FIG. 3 shows the particle size distribution of a secondary pulverizedproduct fabricated by the expanded styrene processing apparatus.

FIG. 4 is a schematic view showing a two-segment type expanded styreneprocessing apparatus according to the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring to the drawings, preferred embodiments of the presentinvention will be explained in detail.

The preset processing apparatus for expanded styrene consecutivelyperforms a series of operations consisting in finely comminutingunneeded expanded styrene, used up for packaging commercial products,illuminating far-infra-red light on the comminuted expanded styrene toreduce its volume and further comminuting the comminuted product torender its size and shape thereof uniform.

A processing apparatus 1 for expanded styrene of an unitary structure,having various units for performing these re respective steps, is firstexplained. Referring to FIG. 1, this unitary type processing apparatus 1includes a first-order comminuting unit 10, for comminuting expandedstyrene 3 injected into a main body unit 2 of the apparatus, a heatingunit 20 for heating the first-order comminuted expanded styrene,referred to hereinafter as first-order comminuted article 4, byilluminating far-infra-red light thereto, a cooing unit 30 for coolingthe first-order comminuted article 4, reduced in its volume by heating,and a second-order comminuting unit 40 for further comminuting thecooled first-order comminuted article 4 to produce granulated producthaving uniform size and shape, referred to hereinafter as second-ordercomminuted article 5. These units are enclosed within the main body unit2 of the apparatus 1.

The first-order comminuting unit 10 includes a pair of comminuting rolls11, 12 as means for comminuting the expanded styrene 3 injected into themain body unit 2 of the apparatus via an injection port 2 a provided inthe main body unit 2, and a first filter 13 for sorting the first-ordercomminuted article 4 comminuted by the paired comminuting rolls 11, 12to permit only the first-order comminuted article 4 of a size not largerthan a pre-set size to pass therethrough, and a scraper roll 14 forscraping the first-order comminuted article 4 not reduced to a size notlarger than the pre-set size to inject the scraped first-ordercomminuted article 4 into a space between the paired comminuting rolls11, 12. The first-order comminuting unit 10 also includes a gate 15 forquantitatively supplying the first-order comminuted article 4 selectedby the first filter 13 to the heating unit 20, and a paddler 16 forstirring the first-order comminuted article 4 in the gate 15 so that thefirst-order comminuted article 4 transmitted through the first filter 13will not be accumulated at the gate 15.

Referring to FIG. 2, the paired comminuting rolls 11, 12 include pluralwavefront-shaped cutting edges 11 b, 12 b, provided at pre-set intervalson the peripheral surfaces of the columnar-shaped rolls 11 a, 12 a. Thecomminuting rolls 11, 12 are provided in the vicinity of the injectionport 2 a in the main body unit 2 parallel to and at a pre-set spacingfrom each other so that the cutting edges 11 b, 12 b mesh each other.The comminuting rolls 11, 12 are adapted for being rotated in reversedirection to each other, as indicated by arrows a and b in FIG. 1, tocrush the expanded styrene 3 charged therebetween to a comminutedproduct of an indefinite shape and a size not larger than a pre-setvalue.

Adjacent to the comminuting roll 12 is arranged a scraper roll 14adapted to be rotated in the direction indicated by arrow c in FIG. 1.This scraper roll 14 scrapes the first-order comminuted article 4 notreduced to the size not larger than the pre-set size to inject thisfirst-order comminuted article 4 to a space between the pairedcomminuting rolls 11, 12. These comminuting rolls 11, 12 and the scraperroll 14 are run in rotation by a driving motor, not shown.

The first filter 13 is configured as a metal plate having pluralcircular orifices approximately 20 to 30 mm in diameter, although theseorifices are not shown. This first filter 13 has its center portionmolded to a curvilinear shape surrounding the paired comminuting rolls11, 12. The first filter 13 is arranged below the comminuting rolls 11,12, by having both ends 13 a, 13 b thereof secured to the inner wallsection of the main body unit 1.

This first filter 13 sorts the first-order comminuted article 4 byallowing the first-order comminuted article 4 from the comminuting rolls11, 12 of the size not larger than the size ofthe orifices to passthrough these orifices, while not allowing the first-order comminutedarticle 4 of the size larger than the orifice diameter to pass throughthe orifices. The first-order comminuted article 4 passed through thefirst filter 13 is supplied to the gate 15, while the first-ordercomminuted article 4 not passed through the first filter 13 is scrapedby the scraper roll 14 so as to be again injected into the space betweenthe paired comminuting rolls 11, 12.

The gate 15 is funnel-shaped and is arranged below the first filter 13so that its upper end opening 15 a faces the first filter 13. The gate15 has its lower opening 15 b smaller in diameter than the upper sideopening 15 a so that the first-order comminuted article 4 injected atthe upper end opening 15 a is temporarily accumulated between theseopenings 15 a, 15 b and so that the first-order comminuted article 4 isdischarged quantitatively via the lower end opening 15 b to moderate theamount of supply of the first-order comminuted article 4 to the heatingunit 20.

On the lower end of the gate 15 is mounted the paddler 16 which iscomprised of a rotary shaft to which is mounted a flat-plate-shapedrotary plate. This rotary plate is run in rotation with rotation of therotary shaft to stir the first-order comminuted article 4 to permit thefirst-order comminuted article 4 to be supplied appropriately to theheating unit 20 without being accumulated in the gate 15.

The heating unit 20 includes a first conveyor 21 for transporting thefirst-order comminuted article 4 supplied from the first-ordercomminuting unit 10, and a far-infra-red heater 22 for illuminating thefar infra-red light to the first-order comminuted article 4 transportedby the first conveyor 21 to heat and reduce the volume ofthe first-ordercomminuted article 4.

The first conveyor 21 includes a pair of driving rolls 23, 24, rotatablyarranged in the main body unit 2, and a belt 25 of glass fibers placedon these driving rolls 23, 24. The first conveyor 21 is adapted toreceive the first-order comminuted article 4 descending from the gate 15of the first-order comminuting unit 10 to transport the received articleto the cooling unit 30.

The belt 25 is adapted for being moved via e.g., a chain at a pre-setvelocity in the direction indicated by arrow d by a driving motor, notshown. The speed of movement of the belt 25 is variable in a range from0.5 to 10.5 m/min and can be set to an optimum velocity depending on thesort or the state of the expanded styrene 3 charged into the main bodyunit 2. The belt 25 is processed on the glass fiber surface with Tefloncontaining carbon for electric conduction.

On the more inchoate side of the first conveyor 21 than the point ofreception of the first-order comminuted article 4, there is mounted aflat-plate-shaped scraper 26 so that its foremost part abuts on the belt25. This scraper 26 scrapes off the material deposited on the belt 25.

The far-infra-red heater 22 has plural heat-radiating plates, generatingfar-infra-red light, so that its longitudinal direction extends parallelto the running direction of ghe belt 25. In the present embodiment, fourrows of heat radiating plates, each having a capacity of 2.0 kW, arearrayed to constitute the far-infra-red heater 22. This far-infra-redheater 22 is mounted at a pre-set separation from the transportingsurface of the belt 25 and has a length sufficient to reduce the volumeof the first-order comminuted article 4 transported by the firstconveyor 21 reliably until the time the first-order comminuted article 4reaches the cooling unit 30. This far-infra-red heater 22 illuminatesthe far-infra-red light on the first-order comminuted article 4 to heatthe first-order comminuted article 4 to a temperature not less than itssoftening point and less than its fusion point. This allows thefirst-order comminuted article 4 to be reduced in volume withoutproducing bad smell or smoke of combustion and without inducingdecomposition on fusion.

The perimetral portion of the far-infra-red heater 22, except itssurface facing the belt 25, is surrounded by an insulating material 27to improve the hest utilization efficiency.

The first-order comminuted article 4, heated by the heating unit 20 andthereby reduced in its volume, is routed to the closure member 30.

The closure member 30 includes a second conveyor 31, for transportingthe first-order comminuted article 4 illuminated by the infra-red lightby the far-infra-red heater 22 and thereby reduced in volume, as thefirst-order comminuted article 4 is allowed to cool, and a cooling fan32 for sending cooling air to the first-order comminuted article 4transported by the second conveyor 31 to promote heat dissipation formthe first-order comminuted article 4.

Similarly to the first conveyor 21, the second conveyor 31 is providedwith a pair of driving rolls 33, 34, rotatably mounted within the mainbody unit 2, and a belt 35 of polyurethane rubber, placed on thesedriving rolls 33, 34. This second conveyor 31 is arranged below thefirst conveyor 21 and accepts the first-order comminuted article 4descending from the trailing end ofthe first conveyor 21 to transportthe first-order comminuted article 4 under cooling.

Similarly to the belt 25 of the first conveyor 21, the belt 35 isadapted to be moved via e.g., a chain by a driving motor, not shown, inthe direction indicated by arrow e in the drawing, at a movementvelocity of, for example, 2 m/min. The first-order comminuted article 4,transported by the second conveyor 31, is set on the belt 35, and ismoved at a movement velocity of, for example, 2 m/min, as it is cooledby the cooling air from the cooling fan 32, so that the first-ordercomminuted article 4 is gradually cooled until it reaches thesecond-order comminuting unit 40.

The cooling fan 32 is a so-called cross-flow fan having a unitarystructure with the motor and, by rotation of an air-blowing drum mountedon a motor rotary shaft, the cooling air is supplied to the first-ordercomminuted article 4 transported by the second conveyor 31 to promoteheat radiation from the first-order comminuted article 4.

The first-order comminuted article 4, transported by the second conveyor31 and cooled, is supplied to the second-order comminuting unit 40.

The second-order comminuting unit 40 includes an inclined conveyor 41,for uplifting the first-order comminuted article 4 cooled by the closuremember 30, a coil conveyor 42 for transferring the first-ordercomminuted article 4, transported by the second conveyor 32 of theclosure member 30, onto the inclined conveyor 41, and a comminuting roll43 for further comminuting the first-order comminuted article 4 upliftedby the inclined conveyor 41. The second-order comminuting unit 40 alsoincludes a second filter 44 for sorting the second-order comminutedarticle 5 comminuted by the comminuting roll 43 to permit only thesecond-order comminuted article 5 not larger than a pre-set size to bepassed therethrough.

The inclined conveyor 41 is made up of a first driving roll 45, adjacentto the driving roll 34 for the second conveyor 31, a second driving roll46 mounted at a higher position than the first driving roll 45, and abelt 47 in the form of a catapillar 47 placed on the first and secondrolls 45, 46. There are mounted on the belt 47 plural uplifting pieces47 a for uplifting the first-order comminuted article 4 at a pre-setinterval. This belt 47 is adapted to be moved by a driving motor, notshown, at a pre-set velocity, in the direction indicated by arrow f,whereby the first-order comminuted article 4 supplied to the inclinedconveyor 41 is uplifted by the uplifting pieces 47 a to a pre-setheight.

The coil conveyor 42 is coil-shaped and has its one end positioned belowthe trailing end ofthe second conveyor 31, while having its other endpositioned below the inchoate end of the inclined conveyor 41. This coilconveyor 42 is adapted to be run in rotation by a driving motor notshown. This coil conveyor 42 is driven to transport the first-ordercomminuted article 4 descending from the trailing end of the secondconveyor 31 to the inchoate end of the inclined conveyor 41.

The comminuting roll 43 is arranged within the main body unit 2 at aposition below the trailing end of the inclined conveyor 41 for furthercomminuting the first-order comminuted article 4 uplifted to a pre-setheight by the inclined conveyor 4.

The comminuting roll 43 has a sole rotary blade and two fixed bladesarranged on both sides of the rotary blade and is run in rotation by adriving motor, not shown, via a V-belt for example, to crush thefirst-order comminuted article 4 descending from the trailing end of theinclined conveyor 41 to produce granulated second-order comminutedarticle 5.

The second filter 44 is formed by, for example, a metal plate, havingplural circular-shaped orifices, not shown, approximately 7 mm indiameter. This second filter 44, arranged below the comminuting roll 43,has its center portion molded to a curvilinear shape to surround thecomminuting roll 43, while having its both ends secured to the innerwall surface of the main body unit 2.

This second filter 44 allows the second-order comminuted article 5 fromthe comminuting roll 43, having the diameter less than the orificediameter, to pass through the orifices, while not allowing thesecond-order comminuted article 5 of the diameter, larger than theorifice diameter, to pass through the orifices, to sort the second-ordercomminuted article 5.

The second-order comminuted article 5, passed through the second filter44, is discharged to outside the main body unit 2 via a discharge port 2b provided in the main body unit 2. The granulated second-ordercomminuted article 5, discharged to outside, is used as a startingmaterial for e.g., injection molding.

The operation of the processing apparatus 1 for expanded styrene,constructed as described above, is now explained.

First, the power source ofthe processing apparatus 1 is turned on, andunneeded expanded styrene 3 is charged into the main body unit 2 via theinjection port 2 a. The paired comminuting rolls 11, 12 operate forfinely comminuting the expanded styrene 3.

The first-order comminuted article 4 from the paired comminuting rolls11, 12, having a size not larger than the pre-set size, is transmittedthrough the first filter 13 so as to be extruded to the gate 15. Forexample, the first-order comminuted article 4 having the diameter notlarger than 20 to 30 mm is passed through the filter 13 and extrudedonto the gate 15.

The first-order comminuted article 4, extruded onto the gate 5, isagitated by the paddler 16, and supplied to the inchoate side of thefirst conveyor 21, moving at a constant velocity, at a constant feedrate. The first-order comminuted article 4 having a size larger than apre-set value is scraped by the scraper roll 14 so as to bere-comminuted by the paired comminuting rolls 11, 12.

The first-order comminuted article 4 supplied to the first conveyor 21is transported by the first conveyor 21 and irradiated with thefar-infra-red light by the far-infra-red heater 22 arranged on thetransporting channel. The first-order comminuted article 4, thusilluminated by the far-infra-red light, undergoes internal heating, sothat its expanded space is destructed and hence the first-ordercomminuted article 4 starts to be contracted. This first-ordercomminuted article 4 undergoes volumetric contraction, withoutdecomposition on fusion, until the time it reaches the trailing end ofthe first conveyor 21, so that the first-order comminuted article 4 isdeformed in a coral shape.

The first-order comminuted article 4 deformed into the coral shape,descends from the trailing end of the first conveyor 21 and is thencesupplied to the second conveyor 31 travelling at a constant rate. Thefirst-order comminuted article 4, supplied to the second conveyor 31 istransported as it is cooled gradually by the second conveyor 31. Thefirst-order comminuted article 4 transported by this second conveyor 31,is exposed to the cooling air flow from the cooling fan 32 so that itsheat dissipation is promoted. Thus, the first-order comminuted article4, at a temperature of the order of 120 to 130°, at the inchoate end ofthe second conveyor 31, is cooled to a temperature of the order of 40°C. at the trailing end of the second conveyor 31.

The first-order comminuted article 4, supplied to the inclined conveyor41, is uplifted by the uplifting pieces 47 a to a pre-set height. Thefirst-order comminuted article 4, uplifted to the pre-set height, isfurther comminuted by the comminuting roll 43 into granulatedsecond-order comminuted article 5.

The second-order comminuted article 5, comminuted by the comminutingroll 43 to a size not larger than the pre-set size, is passed throughthe second filter 44 to descend via the discharge port 2 b to outsidethe main body unit 2. The second-order comminuted article 5, with thediameter of not larger than 7 mm, is discharged via the discharge port 2b to outside the main body unit 2.

With the processing apparatus 1 for expanded styrene, the unneededexpanded styrene 3 is subjected to first-order comminution, followed byirradiation with the far-infra-red light for volume reduction and bysecond-order comminution in this order to prepare the granulatedsecond-order comminuted article 5. The second-order comminuted article5, prepared by the processing apparatus 1 for expanded styrene throughthe processes of first-order comminution, irradiation with far-infra-redlight and second-order comminution, is averaged in size and shape togive a granulated article having the diameter mainly in a range from 2to 3 mm, as shown in FIG. 3. FIG. 3 shows particle size distribution ofthe second-order comminuted article 5 in case the second filter 44 hasthe orifice diameter of the order of 7 mm. If the orifice diameter ofthe second filter 44 is modified, a second-order comminuted article canbe obtained which has an averaged particle size different from that ofthe second-order comminuted article 5 shown in FIG. 2.

The second-order comminuted article 5, prepared by the processingapparatus 1 for expanded styrene according to the present invention, ischarged into, for example, an injection molding machine, so as to bere-used as a starting material for injection molding.

The second-order comminuted article 5, prepared by the processingapparatus 1 for expanded styrene according to the present invention, isaveraged in this manner in size and shape and hence can be re-used as astarting material for injection molding. If the starting material havingvariations in size and shape is used for injection molding, it may be anoccurrence that the material is fused only insufficiently in theinjection molding machine to cause malfunctions thereof or deteriorationin the quality of the molded product. However, the second-ordercomminuted article 5 produced by the processing apparatus 1 for expandedstyrene according to the present invention is granulated to a uniformsize and shape and hence can be used satisfactorily as a startingmaterial for injection molding without producing these inconveniences.

The second-order comminuted article 5 an also be mixed as an ingredientinto the concrete or mortar mixture so as to be re-used a lightweightconstruction material.

A two-segment type processing apparatus for expanded styrene 50, made upof a first processor having a unit for comminuting unneeded expandedstyrene and a unit for illuminating far-infra-red light on thefirst-order comminuted article, and a second processor having a coolingunit for cooling the first-order comminuted article, reduced in volumeon heating, and a unit for further comminuting the first-ordercomminuted article to prepare the second-order comminuted article, isnow explained.

Referring to FIG. 4, the two-segment type processing apparatus forexpanded styrene 50 includes a first processor 51, having a first-ordercomminuting unit 60 for comminuting the unneeded expanded styrene 3 anda heating unit 70 for heating the expanded styrene already subjected tofirst-order comminution (first-order comminuted article 4) byilluminating the far-infra-red light thereon, and a second processor 52,having a cooling unit 80 for cooling the first-order comminuted article4 reduced in volume on heating, and a second-order comminuting unit 90for further comminuting the cooled first-order comminuted article 4 forproducing the granulated second-order comminuted article 5 havinguniform size and shape.

In this two-segment type processing apparatus for expanded styrene 50,the first-order comminuted article 4, processed with first-ordercomminution and heating by the first processor 51, is routed by atransport blower 54 via a transport tube 53 to the second processor 52where the article is cooled and subjected to second-order comminution togive the granulated second-order comminuted article 5.

Similarly to the first-order comminuting unit 10 of the unitaryprocessing apparatus 1 for expanded styrene, described previously, thefirst-order comminuting unit 60 includes a pair of comminution rolls 61,62, as comminution means for comminuting the expanded styrene 3 chargedinto the first processor 51 of the processing apparatus for expandedstyrene 50, a first filter 63 for sorting the first-order comminutedarticle 4 from the paired comminution rolls 61, 62 to permit only thefirst-order comminuted article 4 of the size less than a pre-set size tobe passed therethrough, a scraper roll 64 for scraping the first-ordercomminuted article 4 not larger than a pre-set size to inject it into aspace between the paired comminution rolls 61, 62 and a gate 65 forrouting the first-order comminuted article 4 sorted by the first filter63 quantitatively to the heating uni 70. The first-order comminutingunit 60 also includes a paddler 66 for stirring the first-ordercomminuted article 4 in the gate 65 to prevent accumulation of thefirst-order comminuted article 4 passed through the first filter 63.

The various components of the first-order comminuting unit 60 aresimilar to those of the first-order comminuting unit 10 of the unitarytype processing apparatus for expanded styrene and hence are notexplained specifically.

The first-order comminuted article 4 from the first-order comminutingunit 60 is quantitatively supplied to the heating unit 70.

Similarly to the heating unit 20 of the above-described unitary typeprocessing apparatus for expanded styrene, the heating unit 70 includesa conveyor 75 for transporting the first-order comminuted article 4 fromthe first-order comminuting unit 60, and a far-infra-red heater 72 forilluminating the far-infra-red light to the first-order comminutedarticle 4 transported on the conveyor 75 to heat and reduce the volumeof the transported article.

The respective components of the heating unit 70 are similar to those ofthe heating unit 20 ofthe above-described unitary type processingapparatus for expanded styrene, and hence are not explainedspecifically.

The first-order comminuted article 4, heated by the heating unit 70 andthereby reduced in volume, is supplied to the second processor 52 via atransporting tube 53. Within the first processor 51 is mounted atransport blower 54, whereby the first-order comminuted article 4 heatedby the heating unit 70 is transported via the transport tube 53 to thesecond processor 52.

The cooling unit 80 includes a cooling channel 81, operating as amovement path for the first-order comminuted article 4 charged into thesecond processor 52 and plural stirring blades 82 provided at a pre-setinterval in the cooling channel 81 for causing movement of thefirst-order comminuted article 4 in the cooling channel 81 understirring to promote heat dissipation of the first-order comminutedarticle 4.

The stirring blades 82 are run in rotation slowly at an rpm of the orderof 6 by a driving motor, not shown, to transport the first-ordercomminuted article 4 under stirring to promote heat dissipation of thefirst-order comminuted article 4 transported through the cooling channel81.

The first-order comminuted article 4, cooled as it is transportedthrough the cooling channel 81 under stirring by the stirring blades 82,is routed to a second-order comminution unit 90.

The second-order comminution unit 90 includes a comminution roll 91 forfurther comminuting the supplied first-order comminuted article 4, and asecond filter 92 for sorting out the second-order comminuted article 5pulverized by the comminution roll 91 to permit only the second-ordercomminuted article 5 of a size less than a pre-set value to passtherethrough.

Similarly to the comminuting roll 43 of the above-described unitary typeprocessing apparatus 1 for expanded styrene, the comminution roll 91includes a sole rotary blade and two stationary blades on both sides ofthe rotary blade. The comminution roll 91 is run in rotation by adriving motor, not shown, for further crushing the first-ordercomminuted article 4 transported through the cooling channel 81 to thesecond-order comminution unit 90 to produce the granulated second-ordercomminuted article 5.

Similar to the second filter 44 of the above-described unitary typeprocessing apparatus 1 for expanded styrene, the second filter 92 is ametal plate including plural circular-shaped orifices, not shown,approximately 7 mm in diameter, the second filter 92 sorts out thesecond-order comminuted article 5 by permitting the passage of thesecond-order comminuted article 5 from the comminution roll 91 havingthe size not larger than the orifice size and by not permitting passageof the second-order comminuted article 5 from the comminution roll 91having the size larger than the orifice size.

The granulated second-order comminuted article 5, passed through thesecond filter 92, is discharged outside of the second processor 52 so asto be used as a starting material for e.g., injection molding.

The operation of the above-described two-segment type processingapparatus for expanded styrene 50 is hereinafter explained.

First, the power source of the processing apparatus 50 is turned on, andunneeded expanded styrene 3 is charged into the first processor 51. Thepaired comminuting rolls 61, 62 operate for finely comminuting theexpanded styrene 3.

The first-order comminuted article 4 from the paired comminuting rolls61, 62, having a size not larger than the pre-set size, is transmittedthrough the first filter 63 so as to be extruded to the gate 65. Forexample, the first-order comminuted article 4 having the diameter notlarger than 20 to 30 mm is passed through the filter 63 and extrudedonto the gate 65.

The first-order comminuted article 4, extruded onto the gate 65, isagitated by the paddler 66, and supplied to the inchoate side of theconveyor 75, moving at a constant velocity, at a constant feed rate. Thefirst-order comminuted article 4 having a size larger than a pre-setvalue is scraped by the scraper roll 64 so as to be re-comminuted by thepaired comminuting rolls 61, 62.

The first-order comminuted article 4 supplied to the conveyor 75 istransported by the conveyor 75 and irradiated with the far-infra-redlight by the far-infra-red heater 72 arranged on the transportingchannel. The first-order comminuted article 4, thus illuminated by thefar-infra-red light, undergoes internal heating, so that its expandedspace is destructed and hence the first-order comminuted article 4starts to be contracted. This first-order comminuted article 4 undergoesvolumetric contraction, without decomposition on fusion, until the timeit reaches the trailing end of the conveyor 75, so that the first-ordercomminuted article 4 without undergoing decomposition on fusion and isdeformed in a coral shape.

The first-order comminuted article 4 deformed into the coral shape,descends from the trailing end of the conveyor 75 and is transportedthrough the transporting tube 53 for 5travelling within the secondprocessor 52.

The first-order comminuted article 4, travelling within the secondprocessor 52, is moved as it is stirred by the stirring blades 82 topromote heat dissipation. For example, the first-order comminutedarticle 4, which has retained heat of the order of 120 to 130° C. at thetime point of descent from the trailing end of the conveyor 75, iscooled to approximately 40° C. at the trailing end of the coolingchannel 81. In the drawing, an arrow g indicates the path of movement ofthe first-order comminuted article 4 through the inside of the secondprocessor 52.

The first-order comminuted article 4, cooled to approximately 40° C.,descends from the trailing end of the cooling channel 81 and is furthercomminuted by the comminution roll 91 into the granulated second-ordercomminuted article 5.

The second-order comminuted article 5, comminuted by the comminutionroll 91 to a size not larger than a pre-set size, is passed through thesecond filter 92 and discharged to outside the second processor 52. Forexample, the second-order comminuted article 5 having the size notlarger than 7 mm is discharged to outside of the second processor 52.

With the two-segment type processing apparatus for expanded styrene 50,as described above, the unneeded expanded styrene 3 is processed withfirst-order comminution, then illuminated by the far-infra-red light forvolumetric reduction and further processed with second-order comminutionto produce the granulated second-order comminuted article 5. Thesecond-order comminuted article 5, fabricated by this two-segment typeprocessing apparatus for expanded styrene 50 by the process steps offirst-order comminution, illumination by far-infra-red light andsecond-order comminution, presents a granular appearance having anaveraged size and shape.

Similarly to the second-order comminuted article 5, prepared by theunitary type processing apparatus 1 for expanded styrene, thesecond-order comminuted article 5 prepared by the two-segment typeprocessing apparatus for expanded styrene 50 is charged into, forexample, an injection molding machine so as to be re-used as a startingmaterial for injection molding.

The second-order comminuted article 5 can also be mixed as an ingredientinto the concrete or mortar mixture so as to be re-used a lightweightconstruction material.

What is claimed is:
 1. A method for re-using expanded styrenecomprising: comminuting expanded styrene; sorting the comminutedexpanded styrene by size; illuminating far-infra-red light to only aportion of the sorted comminuted expanded styrene that is smaller insize than a pre-set value to reduce the volume thereof; furthercomminuting the expanded styrene, which has been reduced in volume, toprepare a granulated material; and injection molding the granulatedmaterial to prepare a regenerated article.
 2. The method of claim 1further comprising: re-comminuting a portion of the comminuted expandedstyrene that is larger than the pre-set value.
 3. The method of claim 1,further comprising: cooling the expanded styrene, reduced in volumeafter illuminating the comminuted expanded styrene.
 4. A method forre-using expanded styrene comprising: comminuting expanded styrene;illuminating far-infra-red light to the comminuted expanded styrene toreduce the volume thereof; further comminuting expanded styrene, reducedin volume, to prepare a granulated material; sorting the granulatedmaterial; and injection-molding only a portion of the sorted granulatedmaterial that is smaller than a pre-set value.